<?php
class CdProdcut extends ShopProduct{
	public $playLength;

	function __construct($title,$firstName,$mainName,$price,$playLength=0){
		parent::__construct($title,$firstName,$mainName,$price);
		$this->playLength = $playLength;
	}

	function getPlayLength(){
		return $this->playLength;
	}

	function getSummaryLine(){
		$base = parent::getSummaryLine();
		$base .= ": playing time - {$this->playLength} Minutes";
		return $base;
	}

}